1. Field of Invention
The present invention relates generally to network systems. More particularly, the present invention relates to enabling a gateway network element which does not include an Open Systems Interconnection (OSI) stack to cooperate with a router to manage data communication channel (DCC).
2. Description of the Related Art
The demand for data communication services is growing at an explosive rate. Much of the increased demand is due to the fact that more residential and business computer users are becoming connected to the Internet. To address the demand for data communication services, the use of optical networks, such as a synchronous digital hierarchy (SDH) network or a synchronous optical network (SONET), is becoming more prevalent.
Emerging SDH and SONET standards generally require that gateway network elements within overall networks be able to terminate and to process embedded operation channels. Such embedded operation channels are typically transmitted over data communication channel (DCC) bytes in SONET overhead or, more generally, bandwidth for management information within a signal. Management information is typically extracted from the signal, e.g., information in embedded operations channels is extracted from DCC bytes, by protocol stacks associated with network elements.
Many types of network elements are typically available. Such network elements include, but are not limited to, network elements which support Open Systems Interconnection (OSI) stacks and network elements which support IP-based stacks. As will be appreciated by those skilled in the art, a stack is generally a set of protocol layers, e.g., a stack that is based on an OSI model includes seven protocol layers. Network elements generally include gateway network elements, which are effectively nodes that receive signals or messages from one node and forward the signals or messages to a customer management network.
A gateway network element with an OSI stack is generally arranged to be in communication with network elements and customer networks which send and receive OSI-complaint signals. FIG. 1 is a diagrammatic representation of a gateway network element with an OSI stack in communication with a customer network and other network elements which each have an OSI stack. A gateway network element 104 with an OSI stack is arranged to receive signals from network elements 108 with OSI stacks. When gateway network element 104 receives a signal from a network element 108, gateway network element 104 either forwards the signal to a customer network 112 or to another network element 108, e.g., a signal received by gateway network element 104 from network element 108a may be forwarded to network element 108b and vice versa.
Gateway network elements which have IP or IP-based stacks are generally arranged to be in communication with network elements and customer networks which send and receive IP-complaint signals. FIG. 2 is a diagrammatic representation of a gateway network element with an IP stack in communication with a customer network and other network elements which have IP stacks. A gateway network element 204 with an IP stack is arranged to receive signals from network elements 208 with IP stacks. Gateway network element 204 may receive a signal from either network element 208a or network element 208b, and forward the signal to network element 208b or network element 208a, respectively, as appropriate. Gateway network element 204 may also forward the signal from network elements 208 to a customer network 212.
Typically, network elements which support OSI stacks and network elements which support IP-based stacks or, more generally, do not support OSI stacks, are not interoperable. That is, network elements which support OSI stacks generally are not compatible with network elements which do not support OSI stacks. When an overall network system is to utilize both network elements with OSI stacks and network elements without stacks, the network is effectively designed to include multiple networks, i.e., a sub-network which includes network elements with OSI stacks and a sub-network which includes network elements without OSI stacks. With reference to FIG. 3, an overall network which includes both network elements with OSI stacks and network elements without OSI stacks will be described. Network elements 306, 310 with OSI stacks are connected to each other, and to a customer network 312. Network elements 316, 320, which do not have OSI stacks, are also connected to each other and to customer network 312.
Network elements 306, 310 are not in communication with network elements 316, 320. Network elements 306, 310 communicate with each other and with customer network 312 through dedicated pipes 330, while network elements 316, 320 communicate with each other and with customer network 312 through dedicated pipes 340. Typically, pipes 330 are arranged to carry optical signals which are OSI-complaint, while pipes 340 are arranged to carry optical signals which are not OSI-compliant. Hence, network elements 306, 310 are effectively in a sub-network that supports OSI-complaint signals, while network elements 316, 320 are effectively in a sub-network that supports signals that are not OSI-compliant.
Essentially maintaining separate networks which support different types of signals within an overall network is difficult, as the management of separate networks is often both time-consuming and expensive. When separate networks are maintained, the separate networks are not readily scalable. In addition, redundancy often must be maintained for each network, which further adds to the expense associated with the maintenance of separate networks within an overall network.
Generally, a network element that does not include an OSI stack may not be easily updated to accept OSI-complaint signals. Although the network element that does not include an OSI stack may be altered such that OSI protocols may be terminated within the network element, many developers are unable to develop and to test protocol stacks which would be required to enable OSI protocols to be terminated, and effectively replaced by other protocols. Many developers may not possess the expertise needed, or the time required, to develop and to test protocol stacks that are necessary to terminate OSI protocols within a network element.
Therefore, what is needed is a system which allows an overall network to support OSI-compliant traffic and non-OSI-compliant traffic without requiring that separate networks within the overall network be maintained, and without requiring that a developer modify a network element to terminate OSI protocols when necessary. Specifically, what is needed is a system which effectively allows a gateway network element that does not include an OSI stack to effectively transmit management information contained in DCC channels over a single, shared Ethernet bus to a customer network.